Improved artificial leather



I I UNITED STATES PATENT OFFICE.)

WILLIAM ELMEE, on NEW YORK, Y., ASSIGNOE To ANDREW MCKINNEY, OF BoSToN, MASSACHUSETTS.

Specification forming part of Letters Patent No. 38,785, dated June 2, 1863.

To all whom it may concern:

Be it known that I, WILLIAM ELMER, M. 1)., of the city, county, and State of New York, have invented certain new and useful processes or treatment for producing from other substances than that of the skin of animals a durable leather, which 1 have designated Artificial Leather, and for finishing the same so as to represent any kind of true leather, and for rendering all kinds of leather water-proof; and I do hereby declare that the following in a full, clear, and exact description of the same.

The principal constituents of true leather consist of a gelatino-fibrous compound combined with tannic acid or other agent capable of producing certain changes in the skin of animals, whereby this compound is rendered imputrescible and elastic. The skin of animals, when deprived of the epidermis and other extraneous matter, consists of a fibrous substancethe cutis or coriumwhich is organized of nervous filaments and numerous ramifying fibers intersecting one another in every position, leaving, however, interstices containing a peculiar matter, which, when acted upon by heat and water,yields gelatine. From this result it might be supposed that the corium contains gelatine ready formed, which is not the case. The boiling water modifies the components of the fibrous tissue or corium so as to produce this compound.

The corium consists of-- Centesimally.

Fibrous matter 74.43 Uncoagulated albumen 3.49 Fatty matter 2.32 Extractive 19.76

The effects of tannic acid upon this compound transforms it into a semi-gelatinous mass, by which means leather is formed, or, in other words, this compound is rendered elastic and imputrescible. By the use of similar substances, and by a like process, artificial leather may be formed possessing all the qualities of true leather.

Materials and processes.--First, any kind of suitable cloth, cotton, linen, silk, woolen, or mixed goods may be employed to form the fibrous texture of leather, while albumen, ichthyocolla, extractive and fatty matter, especially prepared for the purpose and in the proper proportions, may be substituted for the other constituents which form the corium or true skin, from which leatheris produced. The action of tannic acid upon this compound transforms it into leather.

In order to combine all the various substances employed in the production of artificial leather, so as to form a perfect chemical union, and one that cannot again be liberated by any ordinary agency, the following method is adopted:

Artificial leather.-First, a suitable cloth is employed, as before stated, to form the fibrous body. The cloth is immersedin a solution of alumina or some one of its compounds for a short time, after which the interstices or meshes of the cloth are filled with a compound of ichthyocolla, albumen, extractive and fatty matter in suitable proportions, which compound constitutes, when combined with tannic acid, a gelatino-fibrous compound, as in true leather. This compound is immersed for from four to six hours in acold aqueous solution of tannic acid or other agent capable of rendering it elastic and imputrescible. After being taken out of this bath and partially dried, itis then immersed again in a solution of alumina. The ichthyocolla compound is then applied as before and immersed in the tannic-acid solution for from twelve to twenty-four hours, or until sufficiently tanned, care being taken that no part of the leather be allowed uncovered by the liquid or in contact with the sides of the vessel. As many coatings of the tanno-ichthyocolla compound may be applied or united together as is necessary to give the desired heft or thickness, as also the feel and appearance, of true tanned leather. Each coating, both before and after being tanned, is rolled between metallic cylinders under pressure. The leather is then Subjected to the coloring process.

A very fine and permanent black or blueblack color is produced by applying a solution of the sesquisulphate of iron in contact with tannic acid. This is applied to one side of the leather only. The sesquisulphate of iron has directly the power of fixing acertain quantity of coloring-matter upon leather recently immersed in a solution of tannic acid. The sesquisulphate of iron is only employed, how- 'ventilattd apartment other hand, if

stopped bottles in contact with the suns rays.

.by any other convenient means.

ever, in this process :when black leather is to be produced. Any color or shade of color may be produced or chemically developed that may be desirable, which wil require the salts of tin and other mordants, &c. After the leather has been dyed it is hung up to dry in a wellfrom which the suns rays are excluded, or it may be dried by any other convenient method. Much care is necessary in the drying, for if conducted too rapidly the leather is liable to crack. On the too slow, it might become moldy, which would be equally injurious to the leather.

The finishing process may now be applied, which consists in rubbing over the surface of the leather a proper quantity of neats-foot oil or other suitable oil, together with the oil of birch. The oil must be evenly laid on, so as to insure a uniform absorption, after which the leather is well rubbed over with a fine cloth or other suitable material in order to remove any oil that has not been absorbed. A coating of flexible varnish is then applied. The varnish is made as followsz caoutchouc dissolved in naphtha, two parts; chemicallytreated linseed-oil, as hereinafter described, one part, by bulk; these well mixed and the whole dissolved in pure sulphuric ether, after which any kind of tinctorial matter desirable may be added. The tinctorial matter, how

. ever, shouldagree in appearance or color with the color previously applied to theleath- The varnish is allowed to stand in wellor other gentle heat for three or four days. The varnish may be applied with a brush or Each coating should be allowed to dry before subsequent ones are applied. After the application of the varnish to the leather it is dried in a room free from moisture, but in contact with a free circulation of atmospheric air,by which means the necessary absorption of oxygen by the linseed-oil takesplace. Theleatheristhenpassed between polished cylinders under pressure, so as to give it a smooth surface. The leather is now in a condition to give it the desired appearance. If, for instance, we wish to give it the appearanc and peculiar grain of morocco-leather, this is done by means of rollers having raised, parallel, straight, or diagonal threads. Black, red, and Turkish morocco, Hungarian, Russian, and any other kind of leather, may be imitated, and a great variety of fancy leather may be made, and any color or shade of color given.

A very fine and durable polished leather, exceeding in beauty what is called glazed orfipatent leather, is produced by applying the following varnish to the leather, after receiving the flexible coating and the smoothed surface.

Take the best kind or pure linseed-oil and rub up with it dry sulphate of lead in quantities sufficient to form in appearance a milky mixture. Expose this, in glass vessels or bottles well corked, to the suns rays, and subject it to frequent shakings for aboutten days. The mucus contained in the oil, together with the sulphate of lead, is then allowed to deposit on the bottom of the bottles, leaving the oil perfectly clear. The oil is then subjected to the decolorizing process by the action upon it of the protosulphate of iron, in conjunction with the suns rays. Equal parts of the oil and iron are employed, the salts previously dissolved in two and ahalftheir weight of distilled water, and the whole well agitated and left to the action of the sunlight for about four weeks. Thus treated the oil is very beautiful, limpid, and colorless. Take equal parts of this oil and Add one fourth part, by weight, of the best copal varnish and such tinctorialmatter as may be required to give the desired tint. The tinctorial matter must be in the finest possible state of division. These are all well agitated together, so as to insure a perfect homogeneous mixture, and brought to the boiling-point and maintained at this temperature for about one hour. It is then set aside in awarm place during the nighttime and cloudy weather, and in contact with the suns rays during the remainder of the time, for about four weeks. The varnish is laid on the leather with a brush and allowed to dry at a temperature not above 150 Fahrenheit, after which it is rubbed carefully over with a fine piece of soft leather or cloth and a little Tripoli or other suitable substance until a fine, smooth, polished surface is obtained. The varnish is again applied and dried, as before; but no further polishing is required. The number of varnished coatings required depends upon the appearance of the surface. Usually from three to six are employed. Each must be very thin and evenly applied and thoroughly dried at atemperature as above stated in a room adapted to the purpose and free from dust or other particles of floating matter. In this way a very fine, beautiful, and durable leather is made, which has the property of resisting strains and of bending without the least crack or injury to the even and brilliant surface, whichis not afiected by the ordinary temperature of heat and cold.

Artificial leather prepared as detailed in this specification may be substituted for all the uses for which real leather isemployed.

Treatment for rendering leather water proof-Leather of any kind may be rendered water-proof and more durable by applying an elastic coating to one side of the leather.

Either side may be subjected to the process. Benzole is first applied to the surface under treatment in order to remove any oil or grease found upon it. A solution of alumina is then applied, followed by a solution of tannic acid. The tannic acid forms with the alumina an insoluble composition, which adheres firmly to the leather. A solution of alumina is again applied and carefully dried. The elastic coating is then applied to the tanno-aluminous pure oil of turpentine.

body, with which it chemically unites. The leather is then passed between revolving cylinders under pressure, the one in contact with the elastic coating heated from 250 to 300 Fahrenheit. The elastic coating is then covercd by the ichthyocolla compound, which is treated in all respects the same as in preparing artificial leather.

The elastic coating is prepared as follows: Uaoutchouc or gntta-percha (or these two substances may he combined) is first submitted to the action of a solvent capable of liquefying them, so as to form a perfect solution, which is placed under pressure in a'suitable apparatus and heat gradually applied and raised to about 300 Fahrenheit, during which time selenium or some one of its compounds, in the liquidform, (or other analogous substances may be employed,) is admitted into the apparatus in contact with the solution, drop by drop, or in verysmall quantities, and the solution in the meantime is kept in constant motion until a selenide of caoutchouc or gutta percha is formed. If the solvent employed to liqnefy the eaoutchouc or gutta-percha contain no oxygen or hydrogen-as the bisulphide of carbon (OSQ-then no other substance is needed in conjunction with the selenide; but, on the other hand, it the solvent employed contain either hydrogen or oxygen, then upon the introduction of the chloride of selenium or chloride of sulphur (if either of these substances be used) an acid is instantly formed, which to prevent or neutralize will require the presence of an alkali. The elastic selenide is a semi-fluid devoid of all unpleasant odor, and possesses, when evaporated to the solid form, all the characteristics of what is called vulcanized caoutchouc or gntta-pereha.

Having thus fully described my invention nd improvements, what I claim as new, and desire to secure by Letters Patent, is+

1. Producing a durable artificial leather from any kind of suitable cloth, woolen, cotton, linen, silk, or mixed goods by first filling the interstices or meshes of the same with a compound of ich thyoeolla, albumen, extractive and fatty matterin the proper proportions, and then subjecting this compound to the action of tannicacid or other agents capable of rendering it elastic and imputrescible or permanent.

2. Alumina or other true mordants employed to unite chemically the various substances used, together with subjecting them to the various processes, manipulations, and applications, as fully set forth in the foregoing specification under the head of artificial leather, and this I claim whether the proportion of the substances employed and the processes, &o.,' detailed in this specification be strictly observed or changed to suit different kinds of materials, as for other purposes, and equivalent substances used without altering the real character of the processes, 850., or the results produced.

3. The finishing of artificial leather so as to represent any kind of true leather, and producing a brilliant and durable polished surface on either artificial or true leather, by subjecting the same to the varnished coatings, compounds, applications, manipulations, &c., as fully set forth in this specification, and for rendering all kinds of leather water-proof, as before described, by the selenide or sulphide of caoutchouc or gutta-percha.

WILLIAM ELME-R.

Witnesses:

E. MAHER,

ROBERT J. TRUSCOT'I. 

